Steam applies more restrictions to limited accounts, to reduce the amount of fraudulent actions by newly created accounts.
This page attempts to explain what you can and cannot do with limited & unlimited accounts.
Steam also has their own page which you can view here.
Steam Guard:
Most interactions in the community need you to have Steam Guard enabled, especially for commenting.
Please make sure that all your bot accounts have at least E-Mail Steam Guard enabled.
I don't think Mobile Steam Guard has any benefits over E-Mail Steam Guard.
What is a limited account?
Limited accounts are Steam accounts which have spent less than $5 USD on the Steam Store.
They have stricter limitations and ratelimits to reduce the amount of spam and scams in the SteamCommunity.
If your account is limited, you can:
- ...comment on profiles of friends
- ...comment on sharedfiles (screenshots, artworks & guides)
- ...comment on discussions
- ...comment on reviews
- ...favorize and unfavorize sharedfiles
- ...follow other users and their workshop
If your account is unlimited, you can do all of the above and additionally:
- ...comment on non-friend profiles
- ...comment in groups
- ...upvote, downvote and funnyvote sharedfiles
- ...add other users as friends
This list is not exhaustive, it just lists features supported by this bot.
For more information, please check out the Steam Support article linked at the top of this page.